Earthenware



UNITED STATES PATENT OFFICE. 4

CHARLES CARROLL GILMAN, OF ELDORA, IOWA.

EARTH ENWARE.

SPECIFICATION forming part of Letters Patent No. 405,028, dated une 11,1889.

Application fil d October 22, 18871 Serial No. 253.133- (No model.)

To all whom it may concern.-

Be it known that 1, CHARLES CARROLL GIL- MAN, a citizen of the UnitedStates, and a resident of Eldora, in the county of Hardin and State ofIowa, have invented certain new and useful Improvements in Earthenware,of which the following is a specification.

My invention relates to porous earthenware products; and it has for itsobject to supply artificially to such structures a fiber inclestructibleby the fire used in converting clays into bricken'products.

. As heretofore made terra-cotta lumber and kindred products resemblewood timber only in that they may be readily operated upon withedge-tools, for the vegetable matters which are incorporated into theplastic composition are driven out by the firing process to which thecompressed plastic mass is subjected subsequent to pressing into form,leaving behind a burned residuum possessing merely the quality ofaffording a tensile strength measured by the tenacity with which theparticles comprising said residuum adhere to one another. by which thewares in question are made provide that cut straw or its equivalent maybe added to the green mixture for the purpose of affording a fiberserving as a temporary means of tying the green wares together, in orderthat they may dry without cracking and be more safely handled whendried; but as the straw is combustible it perishes in the subsequentprocess of firing, leaving the Wares, when burned, destitute of thefibrous strength which characterized them when green.

I propose by my invention to supply a fiber to the clay or clayeycompositions which will remain as an element of the porous brick productafter it has been subjected to the firing process, whereby a high degreeof tensile strength is permanently imparted to the structure. Toaccomplish the result in question, 1 interpose sparsely but intimatelywith the plastic compositions the prepared asbestus of commerce known asasbestine wool.

In carrying out my invention the asbestine wool, in quantitiesdetermined by strength required of burned product, may be sprinkled-Certain of the formulas from time to time upon the exposed surface ofthe clayey compositions containing the vegetable matters as they areturned by the workman with shovels or otherwise upon the floorpreparatory to going to press. I use in this manner from twenty (20)pounds upward of the asbestine wool to about one ton of the burnedcompositions.

In making any of the various porous earthenwares, the manufacture ofwhich, being now familiar to all American clay-workers, needs no specialexplanation in this description, the vegetable matter employed thereinmust not be diminished in quantity because of the addition of theasbestus, for the latter supplies nothing to the porosity of the burnedproduct, inasmuch, as is well known, it will not be destroyed by thefiring process.

Asbcstus when milled and prepared for market usually presents theappearance of wool, and is designated commercially as of long and shortfiber. For the purposes of the present invention I make use, bypreference, of the long fiber, and this comes in the largest quantitiesfrom the mines of North Carolina. After the mineral fiber is properlyand insufficient quantities incorporated into the plastic composition byturning on the floor, as eX-. plained, the mixture is then run throughthe press of the type described as expressive. The composition is forcedthrough the dies of the press onto the cutting-table in hard compressedslabs or forms of the required sizes,

.process in the kilns, where they are burned in the same manner ascommon buildingbrick, the vegetable matters being burned out in thefiring process. The wares thus finished, if broken and subjected toclose examination, will reveal the asbestine fibers but littlediminished in strength by reason of having been under the influence ofthe fire, tightly drawn for the most part like short strings parallelwith the grain of the pressed composition, this arrangement of thefibers and the grain of the ware being caused by the friction which theplastic composition encounters in its enforced passage through the diesof the press.

I hate demonstrated by experiments that Wares such as herein mentionedare possessed of a tensile strength due to the incorporated mineralfibers, which can be obtained in no other Way. This increased tensilestrength is very desirable, if not indispensable, in many cases Wherethe porous brick product in question is now commonly used, and thepresence of the mineral fibers in such of the Wares as are used in theerection of fire-proof structures is not a source of danger, as theadded fibers Which confer the extraordinary tensile strength areincombustible, and hence in no degree detract from the effectiveness ofthe earthenware product as fireproof building material.

Having thus described my invention, What I claim as new, and desire tosecure by Letters Patent, is

A burned porous earthenware product having incorporated therein fibersof asbestine Wool, substantially as described.

Signed at Chicago, in the county of Cook and State of Illinois, this30th day of June, A. D. 1887.

CHARLES CARROLL GILMAN.

\Vitnesscs:

D. W. C. RoWLEY, F. A. DOOLITTLE.

